@Rhysparadox--first of all let me say your last sentence made me laugh.
yes they have always interrupted (meals, ordering drinks, random conversations, you name it) even Sims who weren't nearby, like you say elsewhere on the lot and will walk up to yours. seems like NPCs don't always choose to do other things available on the lot and always prioritise conversation. it helps a little if there's, say, a TV on a pub, that will distract some of them and you might not see as many queued up conversation bubbles.
another example is, you go to the library. you'd expect them to stick to reading/using the computers. instead they gather and chat, often try to drag your Sim into the conversation.
can it be improved? definitely! like we can 'send home' when someone visits, it would be useful to have something like 'stop talking' to remove the unwanted Sim from the conversation. might even be a welcome interaction for Loner Sims. 🙂
